Somalia's pro-government Islamic Courts Union says militant al-Shabab fighters carried out the assassinations of a Somali lawmaker and a senior Islamist military commander this week. The killings have heightened tensions in Mogadishu, with Somali civilians bracing for more violence.

Islamic Courts Union spokesman Abdurahim Isse Adow told reporters in Mogadishu Friday that al-Shabab has created a hit-list of prominent government members and their supporters.

He says his group believes Somali parliament member Abdullahi Isse Abtidoon, who was killed near his home in northern Mogadishu Wednesday, and senior Islamic Courts commander Sharif Mohamud "Karey," who was killed the following day with his son and driver in another part of the capital, were on al-Shabab's list.

Adow says al-Shabab, listed as a terrorist organization by the United States for having links with al-Qaida, has identified certain government officials and supporters as enemies because they have been vocal critics of the militant group.

The slain commander was a close ally of Somalia's Islamist interior minister, Abdulkadir Ali Omar, who was wounded last month in an attack also blamed on al-Shabab. Late Thursday, fighters loyal to Commander Karey carried out a revenge attack on an al-Shabab stronghold in the capital. It was not immediately clear if there were any casualties.

Earlier this week, a group representing Mogadishu's dominant Hawiye clan said that al-Shabab militants had sent death threats to clan elders for participating in peace and reconciliation efforts with Somalia's interim government.

In 2007 and 2008, the Hawiye Tradition and Unity Council endorsed al-Shabab and other opposition groups fighting a bloody insurgency against Somalia's Ethiopia-backed secular government. But council members began distancing themselves from al-Shabab extremists after moderate Islamist cleric Sharif Sheik Ahmed was elected in January to lead a new unity government.

Hawiye elders and clerics have urged President Sharif to quickly implement Islamic law in southern and central Somalia. But al-Shabab, which follows an ultra-conservative form of Islam, opposes the moderate version of Islamic law the president and his U.N.-supported government are likely to put in place.

Al-Shabab also opposes the presence of 4,000 African Union peacekeepers in Mogadishu, who have been in Somalia for the past two years. President Sharif's government has asked them to stay until a Somali national army can be formed to take over security duties.

Soldiers from Uganda and Burundi are currently playing a vital security role by defending the presidential palace, the main seaport and airport from al-Shabab attacks. But the AU mission is also controversial among some Somalis, who blame the peacekeepers for fueling more violence.

At least 10 people were killed and nearly two dozen wounded last Sunday after fighting between al-Shabab and AU peacekeepers broke out around the seaport. Most of the dead and wounded are said to be civilians who had recently returned to the capital after Ethiopian troops withdrew from Somalia in January.

The United Nations refugee agency says that as many as 60,000 Somalis, who fled during Ethiopia's occupation, have moved back to Mogadishu. But the High Commissioner for Refugees says the capital is far from safe and the lack of basic services and shelter is making life difficult for many returning families.